From U.S. Pat. No. 3,875,596, a portable sauna is known comprising a case with a front cover that is hingable for movement from a closed position to an open position. A collapsible seat is placed within the case as well as heating means. This construction has as a disadvantage that the placement of heating means inside the collapsible cabin, which is of relatively small dimensions, can cause the user to come in contact with the heating element. This may lead to the user getting burnt or suffering other discomfort from the heater. Also a part of the space available for the user is occupied by the heater element.